Development and Antimicrobial Evaluation of Binary Ethosomal Topical Gel of Terbinafine Hydrochloride for the Treatment of Onychomycosis

Abstract

The objective of this investigation was to prepare and evaluate the binary ethosomal gel containing terbinafine HCl (TH) to treat onychomycosis. It was reported that binary ethosomes possessed good permeation and stability characteristics than ethosomes. Binary ethosomes of TH were prepared by film hydration method. Prepared binary ethosomes were evaluated for optimized system. Further, ex-vivo skin permeation studies were conducted with rat skin. The formulation of binary ethosomes was converted to gel by using carbopol 934 and evaluated for rheological properties. Antifungal testing of gel was done by cup plate method, using Candida albicans and zones of inhibition of growth were measured. The size, ZP and EE of the prepared binary ethosomes ranged from 200-320nm, -20 to -30mV and 70-92% respectively. In-vitro and ex-vivo diffusion studies indicated that formulation BE4 with greater amount of binary alcoholic phase, showed faster release and increased flux over others. SEM studies revealed that binary ethosomes were in spherical shape. Based on size, EE, drug release profile and antifungal studies, the BE4 formulation was selected for gel preparation. The prepared 0.5% binary ethosomal BE4 gel showed good content uniformity, pH 5.5, no skin irritation, good consistency and better rheological behaviour. Further, antifungal studies of BE4 gel indicated that gel had lower antifungal activity than plain BE4 formulation, probably due to gelling effect in agar diffusion studies. In conclusion, we developed a pharmaceutical gel containing binary ethosomes of BE4 having TH to provide anti-fungal effects useful for the treatment of onychomycosis.